Ok the title is a bit overblown, but I got your attention
I got my Tamron SP AF 17-50mm f/2.8 XR Di-II today and I thought I would share some of my experiences with it. Some of you may know that I ordered this lens after having the bad decentering problems with my DA* 16-50. I am sending the DA* 16-50 back for a refund.
It wouldn’t be fair for me to compare pics between the Tamron and a defective 16-50, so I’ll comment on what I like about the Tamron 17-50:
Size: Shorter, narrower and lighter than the 16-50. This means I can actually use the built in flash with the Tamron. I could not detect any lens shadow even at the widest setting. This was something I was disappointed about with the 16-50 because the lens shadow was pretty extreme from 16mm out to about 35mm. I don’t use built-in flash much except for fill, but even in fill you can see interference. And sometimes, you just need flash, and if this lens is to be my baseline lens, I don’t want to always have to go put on my AF360FGZ flash to get a quick snapshot.
Build: The Tamron feels very sturdy and is built “tight.” No lens creep whatsoever (nor was there creep in the 16-50. The 16-50 is very well built as well.) I don’t even need the zoom lock at all. In fact the zoom and focus are well damped. Also, there is no play whatsoever in the extension tube, even when at a maximum. I also prefer the single tube extension of the Tamron to the double tube of the 16-50. There is no “hesitation” in the zoom due to the engaging of the second tube. It is consistent throughout.
Ergonomics: I much prefer the zoom ring on the Tamron. It is wider, and in a more convenient location (away from the body more) than the 16-50. I found the zoom on the 16-50 to be relatively uncomfortable since I had to spin the ring that is smaller and closer to the body under the flash overhang. This can be especially annoying when using the grip, and/or taking vertical shots. I would guess that most people with a zoom lens use the zoom ring much more frequently than the focus ring. For the life of me I don’t know why Pentax (Tokina) made the zoom ring small and closer to the body and the focus ring huge on the 16-50. Maybe for a macro prime, but why on a baseline, kit-upgrade, AF zoom?
Focus speed and sound: Focus is very fast and accurate. I did not notice it to be any slower at all. Sound is typical.
Support: Tamron has a 6-year warrantee.
IQ: Excellent. In fact I compared it with the DA* 50-135 (at 50mm) and the FA50/1.4. To see any difference at all, you need to view at 100% crop and wide open. The differences were not significant enough at this point for me to take time to make the crops and post them.
I am not writing this to criticize the 16-50. I am sure that if one gets a good copy it is a great lens. Some people here have shown fabulous shots with it. I love all my Pentax glass. I just think that in my case, things worked out for the better because after using both lenses, I really prefer the Tamron! Weather sealing and SDM to me are not worth it to lose all the other advantages I outlined above for this particular lens choice.
OK, I am done buying lenses for a while…
UPDATED: test pics below in post #15
Last edited by PentaxPoke; 06-05-2008 at 05:00 PM.